Also, re: monitor mixes. The Behringer mixers (x32) with monitors (p16) are, frankly, about the best deal going for anything less than cost-no-object type installs.
Yes, Behringer. They bought a little company called Midas, and their stuff is actually great. Not recommending anything but their pro-audio stuff, though.
So if you're building a sound system, you should really look at the X32. Don't just take my word for it; check the reviews.